Angiographic findings in patients with refractory unstable angina according to troponin T status

The CAPTURE (C7E3 fab AntiPlatelet Therapy in Unstable REfactory angina) trial enrolled patients with refractory unstable angina and documented a therapeutic benefit for abciximab, a platelet glycoprotein IIb/IIIa receptor antagonist, that was particularly evident in patients with elevated troponin T (TnT) levels. In the current study, we related the angiographic data to the TnT status of the CAPTURE patients.

In 853 patients, angiographic data at baseline and 18 to 24 hours after treatment were available and assessed by an Angiographic Committee with respect to TIMI flow, lesion severity, and visibility of thrombus. TnT levels >0.1 microg/L were found in 30.9% of the patients. Before randomization, thrombus was visible in 14.6% of TnT-positive patients (TnT levels >0.1 microg/L) and 4.2% of TnT-negative patients (P=0.004). Complex lesion characteristics B2+/C (72.0% versus 53.9%; P<0.001) and TIMI flow <2 (15.6% versus 5. 1%; P<0.001) were more frequent in TnT-positive patients. Abciximab was effective with respect to reduction of visible thrombus, increase of TIMI flow, and reduction of cardiac events in TnT-positive patients only. Multivariate analysis identified TnT status, but not angiographic findings, as an independent predictor for both outcome and efficacy of treatment with abciximab.

Complex lesion characteristics and visible thrombus formation at baseline were significantly linked to TnT elevation. However, TnT status was a more powerful predictor of increased cardiac risk and efficacy of treatment with abciximab than either. Relative to the angiogram, TnT can thus be considered a more sensitive marker for the underlying pathology, identifying patients with unstable angina who will particularly benefit from antiplatelet treatment.